The invention concerns the use of a composition for preserving organs and limbs.
When organs or limbs are removed for a transplant they have to be stored until they are used in such a way that they suffer as little damage and spoiling as possible. Limbs which were severed and which are to be sewn back on again must be stored in a protected condition until they are integrated into the blood circulation again. The organs or limbs have to be protected from mechanical damage but also from harmful effects which occur by virtue of the fact that they are not integrated into the blood circulation. In order to retard the degradation process or the onset of decay which occurs as soon as the organs or limbs are separated from the circulatory system, various methods have been developed. One possible option involves storing the organs or limbs in liquid perfluorocarbons. Perfluorocarbons have the advantage that they are inert, that is to say they do not react with the organ tissue. Perfluorocarbons also have the advantage that they have a high absorption capability for oxygen so that when they are stored in perfluorocarbons the organs or limbs can be supplied with oxygen. That prolongs the survival time of the organ or the limbs. Use of the perfluorocarbons was an important advance in transplant medicine.
A disadvantage when using perfluorocarbons however is that they are of a very high density which is far above the density of the organs or limbs. For that reason the organs or limbs float up in the liquid instead of being immersed therein. In order to provide that the organ is enclosed by perfluorocarbons it is necessary to apply a force for counteracting the buoyancy. In general that is done by the organs or limbs being held under the surface of the perfluorocarbons with holding devices. It is only then that it is ensured that they are adequately supplied with oxygen and do not come into contact with the environment which is harmful to organs or limbs. However capillary systems in the tissue can be mechanically damaged by the holding devices. The damage to the structures may be so extensive that a transplant or sewing back on is no longer a possibility.
A further disadvantage of perfluorocarbons is their low dissolving power for other compounds. It is therefore not possible to add to a preserving solution of perfluorocarbons, active substances which can perform a function that is helpful in terms of preserving the organs and limbs.
It is known for organs to be stored at very low temperature, that is to say to effect cryopreservation. It will be noted however that for that purpose water first has to be removed from the tissue so that the cells do not burst during the freezing process. Storage is effected in the case of cryopreservation at temperatures in the range of −100° C. to −180° C. Cryopreservation is suitable for cells which are not very sensitive to mechanical stresses, but it leads to major problems in relation to organs and delicate tissues.
The demands on a composition for preserving organs or limbs are thus many and varied.